US 5,563,734 A · Durable low-emissivity solar control thin film coating

Abstract

An infrared reflecting interference filter capable of transmitting a desired proportion of visible radiation while reflecting a large portion of incident solar radiation is provided. The filter comprises a transparent substrate onto which is deposited a dielectric layer, followed by metal and dielectric layers. In between each of the dielectric and metal layers is deposited a precoat layer that promotes adhesion between the dielectric and the metal. One aspect of the invention is the use of a film comprising nickel and chromium nitride for each of the metal precoat layers. These precoat layers are thin so that there is less absorption of visible light but yet maintains good adhesive properties. Another aspect of the invention is the use of silver as the metal layer. Specifically, silver is sputtered in an atmosphere containing a mixture of nitrogen and argon or other inert gas. It was found that the presence of nitrogen produces a silver layer that is more durable than silver films sputtered in an atmosphere containing essentially pure inert gas. In one embodiment, the interference filter comprises a glass substrate onto which is deposited a thin-film design consisting of five layers, namely: titanium dioxide, nickel-chromium nitride, silver, nickel-chromium nitride, and silicon nitride.

Claims29

Dependent claims

A thin film interference filter comprising:

a transparent substrate;
a first substantially transparent dielectric layer comprising titanium dioxide;
a first metal precoat layer wherein said first metal precoat layer comprises a material selected from the group consisting of the combination of nickel with chromium and the combination of nickel with chromium nitride;
a partially reflective metal layer;
a second metal precoat layer comprising a mixture of nickel metal and chromium nitride;
and
a second substantially transparent dielectric layer.

4 more elements

A method for the production of a durable thin film interference filter on a transparent substrate comprising the steps, in sequence, of:

depositing a first substantially transparent dielectric layer onto said substrate;
depositing a first metal precoat layer wherein said first metal precoat layer comprises a material selected from the group consisting of the combination of nickel with chromium and the combination of nickel with chromium nitride;
depositing a partially reflective metal layer;
depositing a second metal precoat layer comprising a mixture of nickel metal and chromium nitride;
and
depositing a second substantially transparent dielectric layer comprising the steps of:
(a) providing a cylindrical magnetron having a rotatable target and having magnetic means disposed at an angle of approximately 20.degree. to 60.degree. from normal relative to said substrate;
and
(b) moving said substrate towards the rotatable target so that dielectric material is reactively sputtered and focused onto the substrate at an acute angle as the substrate approaches the target.

6 more elements

Dependencies are inferred from the claim text.

Durable low-emissivity solar control thin film coating

Life of this patent

Durable low-emissivity solar control thin film coating

Life of this patent

Abstract

Claims29